external radio issue with ic-756p2 and RTL-SDR

iz1fks
Posts: 36
Joined: Sun Mar 14, 2021 1:50 pm

external radio issue with ic-756p2 and RTL-SDR

#1

Unread post by iz1fks »

Hello,

I have set up here a panadapter with ic-756pro2, with the RTL-SDR on the 1st IF freq.

I have a few issues: when I'm changing frequency with the radio vfo the spectrum update looks slow and not fluid at all. I don't understand the reason since using for example qo-100 upconverter feature moving the radio vfo the receive frequency on the sdr is really very good.

This behaviour appers only with bit SDR=>radio and RADIO=>SDR frequency tracking. If I disable SDR=>radio tracking spectrum is always updated during vfo rotation seeing signals moving left and right according to vfo.

I think that with CAT connection in panadapter mode the frequency bar under the spectrum/waterfall should be always updated tracking the radio VFO without interfering with spectrum/waterfall that now is freezing, while an option button shuold be available to disable the point and click function that change the frequency on the rig.

my setup:
SDR console 3.0.21
RTL-SDR
ICOM IC-756pro2 with cat control rs232, serial speed 19200bd

RTL-SDR is connected to the first IF tap of the rig (64.455 MHz).

PC: Xeon E5450 @3GHz quad core with 8 GB ram win7 x64.

In addiction if the sdr should be set off and then on gain the syncro with rig is lost and i have to restart the software.

73 de Phil, iz1fls

iz1fks
Posts: 36
Joined: Sun Mar 14, 2021 1:50 pm

Re: external radio issue with ic-756p2 and RTL-SDR

#2

Unread post by iz1fks »

I have moved to RSP1A, but the behaviour is always the same, issues with this syncro in External radio when tracking is active. why the spectrum is freezed? why without syncro or syncro used for qo-100everything is working?
73 de Phil,iz1fks

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: external radio issue with ic-756p2 and RTL-SDR

#3

Unread post by Max »

iz1fks wrote: Sun Mar 14, 2021 1:59 pm I have a few issues: when I'm changing frequency with the radio vfo the spectrum update looks slow and not fluid at all. I don't understand the reason since using for example qo-100 upconverter feature moving the radio vfo the receive frequency on the sdr is really very good.
Phil did you see this page, particularly the part near bottom of page about Polling Interval on Omnirig?

https://www.sdr-radio.com/external-radio#Omni-Rig

Also, are you sure to use the correct version of Omnirig 1.xx only from DX Atlas website?

https://dxatlas.com/OmniRig/

A lot of people seem to try Omnirig 2.xx which is modified version from third parties but as far as I recall it causes problems with SDRC.

73

Max

iz1fks
Posts: 36
Joined: Sun Mar 14, 2021 1:50 pm

Re: external radio issue with ic-756p2 and RTL-SDR

#4

Unread post by iz1fks »

omnirig 1, 100ms the minimum allowed. omnirig is not the issue since with no IF mode everything works and the frequency is alwas updated correctly, it a spctrum issue . I use omnirig even for qo-100 tested configuration with a 1200bps cat IC475, no issue there. There is an issue with panadapter used with IF output.

73 de Phil

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: external radio issue with ic-756p2 and RTL-SDR

#5

Unread post by Max »

OK Phil. No issues there then. Sorry, I have no idea what is causing the issue you are having. If you solve it please come back and report here because I'd be interested in the answer.

73

Max

jdow
Posts: 800
Joined: Mon Aug 10, 2020 8:17 pm

Re: external radio issue with ic-756p2 and RTL-SDR

#6

Unread post by jdow »

Done correctly, which I cannot answer for OmniRig of any sort, the Pro II (and other ICOM radios that use the same protocol) sets its own pace for updates as with all commands. You cannot send a command to the radio before the preceding command is acknowledged or denied. I've found that something on the order of half a second is a good default delay if nothing is heard from the Pro-II. So if a command is outstanding and a poll request is made you get this "take a half second or more nap" situation.

My ProII is dead. (The TX RF deck may have a future life.) So I cannot take this further. The ICOM protocol is a protocol from heck, not quite Hell. It is SLOW at 19.2 k bits per second. A complete display update is really slow if done naively and simply rather slow if a memory entry is sacrificed and a move panel to memory followed by read memory is used. (Going the other way this is also the faster way in general.)

It sounds like the protocol delays are also delaying SDRC itself for some unknown reason. It is not impossible that you are demanding more of the video card than it can deliver to the screen.

Good luck with it.

{o.o}

iz1fks
Posts: 36
Joined: Sun Mar 14, 2021 1:50 pm

Re: external radio issue with ic-756p2 and RTL-SDR

#7

Unread post by iz1fks »

jdow wrote: Mon Jul 24, 2023 12:16 am Done correctly, which I cannot answer for OmniRig of any sort, the Pro II (and other ICOM radios that use the same protocol) sets its own pace for updates as with all commands. You cannot send a command to the radio before the preceding command is acknowledged or denied. I've found that something on the order of half a second is a good default delay if nothing is heard from the Pro-II. So if a command is outstanding and a poll request is made you get this "take a half second or more nap" situation.

My ProII is dead. (The TX RF deck may have a future life.) So I cannot take this further. The ICOM protocol is a protocol from heck, not quite Hell. It is SLOW at 19.2 k bits per second. A complete display update is really slow if done naively and simply rather slow if a memory entry is sacrificed and a move panel to memory followed by read memory is used. (Going the other way this is also the faster way in general.)

It sounds like the protocol delays are also delaying SDRC itself for some unknown reason. It is not impossible that you are demanding more of the video card than it can deliver to the screen.

Good luck with it.

{o.o}
Thanks for your answer.
if your assumption was right, why I don't see this effect with qo-100 setup using an ICOM 475 at 1200bps ? why the behaviour of SDR-=> Radio and Radio=> SDR is not working correctly? Why if I disable "IF output" and select "antenna: same frequency of external radio" the spectrum update is extremely fast and everything ilooks working right?
This looks like as an issue with "IF output" external radio feature. In HDSDR I had no freeze or spectrum issue with cat, even if now that i have upgraded to RSP1A it looks imopssibile to remove center dc spike.
73 de Phil

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